Safety device for locks



Feb. 11, 1941. s. s. KARAVIA 2,231,535

SAFETY DEVICE FOR LOCKS Filed June 11, 1940 Fiai Fia.2

SOPHIE Sf EAR/l WA INVENT OR.

ATTORNEY.

Patented Feb. 11, 1941 UNITED STATES PATENT OFFICE SAFETY DEVICE FOR LOCKS Sophie S. Karavia, New York, N. Y. Application June 11, 1940, Serial No. 339,864 9.Claims. (01. 70 425) My invention relates to safety devices for looks can be closed by a tongue !8 on a sliding bar it and has particular reference to devices for prefitted in a corresponding slot in the disc l3. The venting opening of door locks. member or bar I9 has a hook 2c on the end for In certain establishments such as banks, stores, manually moving the bar so as to open or close workshops etc, the doors must remain closed and the keyhole. The disc is with the sliding bar is 5 locked during the night, and there is usually a covered by a number of discs 2|, 22 and 23, rotadanger that an unauthorized person may obtain tively held together on a bolt 2 fastened to the a key and gain admittance during the night. The first disc lit by a nut 25. A suitable recess 26 is same applies to private houses and apartments provided in the lock cylinder 4 for the end of the 10 when the occupants leave temporarily the prembolt 24 with the nut 25. The lock cylinder is also 10 ises, locking the outside doors. fastened to the disc It by screws 43. A ring 21 My invention has for its object to provide a encloses peripherally the first disc l3 and is atsafety device which may be added to an ordinary tached to the plate 6 by screws 28. It is provided lock for preventing insertion of a key into the with a slot for the end of the sliding bar IS. A

keyhole. I provide for this purpose a member second ring 29 is rotatively fitted in the first ring, 1 supported outside the lock and adapted to be extending above the fir t r a d ac d y manually moved into a position in which the key- Screws 353 to the Second s 2 A third ring 3 s hole is closed so that the key cannot be inserted. p d inside th c d ring 29 and S ast d The member is covered by a number of discs with o a t ird d sc 22 by Screws 3 e r g 32 is go eccentric openings for the keyhole, the discs havtapered on the inside, slidably engaging the taing means for locking the sliding member in a key- Dered pe p e y o a ou d 3- hole closing position. By placing the discs in 2. D s nd 22 r p v d h w c n ncertain position which is known to the rightful ri sl ea h, 6 a 31, wi n opening 38 owner of the key, the member is released and n between them, the slots being also concentric with be Withdrawn thereby exposing the keyhole. The the bolt 24 or its hole 39 (Fig. 4). The last disc 25 discs may be provided with a plurality of symbols has oov s 4 d M Corresponding to the Slots for indicating the operative positions in which the in e cs 2| a d The bolt 4 has a rou d locking member is released. head 42 sunk into the last disc 23 so that it cannot My invention is more fully described in th be turned or unscrewed from the outside. To

accompanying specification and drawing i prevent the removal of the lock cylinder 4 it is 30 which fastened to the disc I 3 by screws 43 passing Fig. 1 is a sectional elevational view of my device through 1 8 in connection with a door lock; e S10t$ and t g o ves e e gaged by a pin Fig. 215 a, front iew of the same; 45 extending from the sliding bar 19. The pin Fig, 3 is a detail ie of a keyhole losing controls the position of the bar, the latter being 35 member; in the keyhole closing or operative position when i 4 i a detail View of a locking disc; the pin is placed in the slots 36 and groove an and Fig. 5 is a rear view of a locking cylinder; in the k yh le p n position w placed in Fig, 6 is a detail iew f a keyhole di d the slots 31 and groove 4|. For moving the bar Fig. 7 is a sectional View taken on the line 1'l from one position to the other, the discs are ro- 40 of Fig. 3. tated until all their openings 38 are placed on a My safety device is shown in the drawing as apline with the axis of the sliding bar 59. Since the plied to a door look I having a sliding bolt 2 with slots and grooves cannot be seen from the outside, a handle 3 (shown partly broken away) at one side he r t p n f the discs is determined y and a locking cylinder 4 at the other, usually outer pl certain marks on their peripheries pp 45 side, the lock being fitted in a door 5. A plate 6 site a stationary mark 46 on the first ring 21. The is attached to the door on the outside by bolts 1 rings are provided for this purpose with numerals with concealed heads 8 so that the bolts cannot 7, 48 a d l s or ot S b Sym s 9- be unscrewed from the outside. The plate has an For turning the outer chsc 23 it is provided with a 50 opening la threaded for the threaded end ll of pin r screw 50, the inner discs being turned by 50 the lock cylinder 4. The latter is also attached to rotating their ringsthe lock 1 by screws [2. A disc I 3 is attached to The discs have round openings 5! registering the plate 6 by screws l4 passing through holes IS. with the keyhole H. The openings are closed by The disc is provided with an opening 16 for the discs 52 with keyhole slots 53. The discs are re- 5 keyhole I! in the lock cylinder. The opening [6 tained in their po'sition'by their tapering periph- 55 2 r eries engaged by correspondingly tapering sides of the openings 5| as shown in Fig. 1. These smaller discs protect the main keyhole from dirt etc.

With my safety attachment it is impossible to insert the key into the keyhole I 1 of the lock cylinder if the pin is placed in the outer slots 31. The rings can be turned with the pin in the outer grooves and slots without enabling the pin to pass into the inner grooves or slots 36. This may happen only if all the discs are aligned with the openings 38 in line with the pin 45 and bolt 24. This position of the discs cannot be found by trial and it is necessary to know the exact combination of the symbols 4?, 48 and 59. When the discs are correctly placed, the bar I9 is withdrawn by pulling on its hook 20. The bar may be then left in the open or inoperative position if desired, or it can be shifted again into the closing position, locking it by turning the discs in different directions.

It is understood that my safety device may be modified without departing from the spirit of my invention as set forth in the appended claims.

I claim as my invention:

1. A safety device for a lock comprising a plate, means to support the plate in front of a keyhole of the lock, the plate having an opening registering with the keyhole, a manually operable member supported on the plate adapted in its operative position to close the keyhole for preventing insertion of a key, a plurality of discs rotatively supported on the plate one on top of the other and overlapping the opening, the discs having openings registering with the keyhole in a certain position of the discs, and means on the discs for locking the member in the keyhole closing position, the member being adapted to be manually withdrawn into the keyhole opening position when the discs are placed in a corresponding position, the discs having symbols for indicating their positions.

2. A safety device for a lock comprising a plate, means to support the plate in front of a keyhole of the lock, the plate having an opening registering with the keyhole, a manually operable member slidably supported on the plate adapted to be moved for selectively closing and opening the keyhole, a plurality of discs rotatively supported on the plate one on top of the other and overlapping the opening the discs having openings corresponding to the keyhole opening, a projection extending transversely from the sliding member, the discs havingopenings for the projection, and cam-shaped portions on the discs engaging the projection, one cam-portion corresponding to the keyhole closing position of the member and the other to the keyhole opening position, the discs having passages between the two portions for moving the member, the discs having symbols for indicating their positions.

3. A safety device for a lock comprising a plate supported in front of a keyhole of the lock, the plate having an opening registering with the keyhole, a sliding member on the plate adapted to close the keyhole opening for preventing insertion of a key, a plurality of discs rotatively supported on the plate eccentrically with the keyhole and having openings registrable with the keyhole, a pin extending from the sliding member, the discs having slots forming cam-shaped surfaces engaging the pin, the outer disc having grooves corresponding to the slots of the'inner discs, each disc having a passage between its two'slots, one slot being insideihe other, the

bar closing the keyhole opening when the pin is in the inner slots and opening the keyhole when the pin is in the outer slots, and means to indicate the positions of the discs.

4. A safety device for a lock comprising a plate supported in front of a keyhole of the lock and having an opening registering with the keyhole opening, means to attach the lock to the plate, a sliding member on the plate adapted to be manually moved for selectively closing or opening the keyhole, a plurality of discs rotatively supported on the plate one on top of the other eccentrically with the keyhole opening, the discs having two concentric slots each, the outer disc having grooves corresponding to the slots, the inner and outer slots having a communicating passage therebetween, a pin extending from the sliding member engaging the slots, the member being in the keyhole opening position when the pin is in the outer slots and in the closing position when the pin is in the inner slots, the member being set free for movement between the slots when the discs are aligned with the slot passages extending along the axis of the sliding member, and means to manually rotate the discs.

5. A safety device for a lock comprising a plate, means to support the plate in front of the keyhole of' the lock, the plate having an opening registering with the keyhole a sliding member on the plate adapted to close the opening, a plurality of discs on the plate, a bolt fastened to the plate and rotatively supporting the discs, rings on the peripheries of the discs successively and concentrically engaging each other, the discs having openings registrable with the keyhole opening, the discs being further provided with inner and outer slots, each pair of slots being in a communication with each other at one point, a pin extending from the sliding member passing through the slots, the bar being adapted to be manually shifted between its operative and inoperative positions for closing and opening the keyhole when the discs are manually turned into positions in which the communicating openings between the slots are in line with the axis of the sliding member, the outer slots corresponding to the inoperative position of the member and the inner slots to its operative position, and movable discs for closing the keyhole openings in the discs.

6. A safety device for a lock comprising a plate supported in front of the keyhole in a lock cylinder, means to attach the lock cylinder to the plate, a movable member on the plate for closing the keyhole, a plurality of discs rotatively supported on the plate covering the movable member, the discs having arcuate slots, inner and outer, and a pin extending from the movable member into the slots, theinner and outer slots having a communicating groove the movable member being released for movement between its two extreme positions when the discs are placed in a position with the communicating slots in line with the axis of the member.

7. A safety device for a lock having a lock cylinder for operating a door bolt, comprising a plate, the lock cylinder being screwed into a hole in the plate, means to prevent unscrewing of the lock cylinder from the plate, a member slidably supported on the plate for selectively closing or opening the keyhole of the lock cylinder, a plurality of discs on the plate, a bolt mounted on the plate rotatively supporting the discs, the discs having openings registrable with the keyhole, the discs being provided with means for permitting the movement of the sliding member in one position of the discs and for preventing said movement in other positions of the discs, and means to indicate different positions of the discs.

8. A safety device for a lock comprising a plate, means to attach the plate to a cylinder of the lock, the plate having an opening for the keyhole of the lock, a sliding member on the plate adapted to be manually moved for closing or opening the keyhole, a plurality of discs covering the sliding member, the member having a handle extending outside the discs, the discs having inner and outer arcuate slots having a communicating slot at one point, a pin extending from the sliding member passing into the slots, and means to manually rotate the discs for placing them into a position in which the communicating slots are in line with the line of movement of the sliding member thereby releasing the member for movement between it opera-- tive and inoperative positions, the member being prevented from movement when the discs are turned for disaligning the communicating slots.

9. A safety device for a lock comprising a plate, means to attach the plate to a cylinder of the lock, the plate having an opening for a keyhole of the look, a sliding bar supported at the outer side of the plate, adapted to close the keyhole opening in its operative position, a plurality of discs on the plate covering the main portion of the sliding member, a bolt rotatively supporting the discs on the plate, the lock cylinder having a recess for the bolt, the discs having openings registrable with the keyhole opening in the plate, the discs having two concentric arcuate slots each, a pin extending from the sliding member into the slots, each pair of slots having a communicating slot, the sliding member being rendered free for movement between its operative and inoperative positions when the communicating slots in the discs are placed in line with the line of movement of the sliding bar, the pin being adapted to be retained in the inner or outer slots when the discs are rotated for displacing the communicating slots, and means on the discs for indicating their difierent positions.

SOPHIE S. KARAVIA. 

